I only ever tried widowhood for a couple for years back in the 90s, as Andy was doing well on it, but I just didn't like it so have stuck with natural since, granted I don't do much from the shorter races, mainly because I can't be asked to keep training them, but they do ok from the distance, I'm happy with that.
So because of that I can't really comment on the system or how to train the birds on it, however I would say that most of our fed members probably do fly widowhood but they all have their own variations on how they do it !!
I would say that the top 3 sprint fliers in our club at the moment are the two Alan's and young Danny, young Danny races natural and topped the fed twice this year hens, one of the Alan's races widowhood, he was racing cocks and hens but after having major heart surgery last winter now just races 18 cocks on which I'd call the traditional method of showing the hen and having her in the box when the cock returns, he also doesn't race anything over 3 years old, regardless of how well it's done.
The other Alan, also on widowhood, just puts half dozen hens in with his older cocks just before basketing to get them nicely worked up for the race, he races a lot more birds so it takes him far too long messing about with putting hens in every box. I think he did say that his yearlings are raced the more traditional way as he found that they got a bit too stressed the other way. I do know of other fanciers who just race to the box and don't show the hens at all once racing starts, I do know one thing for certain though, nearly all of the top fliers will have at least one trick up their sleeves that they won't tell you about lol
The one thing that both Alan's and Danny do though is, train, train and keep on training, they must get through some fuel and tyres every year